Carpanter's Star

I finished quilting my Carpanter's Star Quilt before the Thanksgiving Holiday.  The binding is now done.  Its made out of vintage 1970's and 1960's fabrics.  Just a scrap quilt with fun Baptist Fan Quilting.  I think you can see the quilting on this picture. 

Singer 15

I am hoping someone out there can help me.  I am using my normal machine and for last couple days, I have been trying to sew binding onto a quilt, and I can sew maybe three or four inches and the top thread breaks.  I have cleaned the tension, cleaned the entire machine, changed needles.  I even switched different brands of thread and I am still having the same problem.  I even adjusted the foot pressure.  It sews fine while doing patchwork, just cannot get it to work on sewing binding on.

If any one is familiar with a Singer 15, let me know what I might be doing wrong.